/**
 *@Description 拖拽和缩放
 *@Author huangpeng
 *@Date 2023/7/1 14:55
 */
export default {
  bind(el, binding, vnode, oldVnode) {
    if (binding.value === false) {
      return
    }
    // 拖拽
    drag(el);
    // 最大化
    resize(el);
  }
}

/** 拖拽方法 */
function drag(el) {
  //获取弹框头部（这部分可双击全屏）
  const dialogHeaderEl = el.querySelector('.el-dialog__header');
  //弹窗
  const dragDom = el.querySelector('.el-dialog');
  //头部加上可拖动cursor
  dialogHeaderEl.style.cursor = 'move';
  dragDom.className += ' el-drag-dialog';
  // 获取原有属性 ie dom元素.currentStyle 火狐谷歌 window.getComputedStyle(dom元素, null);
  const sty = (function () {
    if (window.document.currentStyle) {
      return (dom, attr) => dom.currentStyle[attr];
    } else {
      return (dom, attr) => getComputedStyle(dom, false)[attr];
    }
  })()

  dialogHeaderEl.onmousedown = (e) => {
    // 鼠标按下，计算当前元素距离可视区的距离
    const disX = e.clientX - el.offsetLeft;
    const disY = e.clientY - el.offsetTop;
    const screenWidth = document.body.clientWidth; // body当前宽度
    const screenHeight = document.documentElement.clientHeight; // 可见区域高度(应为body高度，可某些环境下无法获取)
    const dragDomWidth = dragDom.offsetWidth; // 对话框宽度
    const dragDomheight = dragDom.offsetHeight; // 对话框高度
    const minDragDomLeft = dragDom.offsetLeft;
    const maxDragDomLeft = screenWidth - dragDom.offsetLeft - dragDomWidth;
    const minDragDomTop = dragDom.offsetTop;
    const maxDragDomTop = screenHeight - dragDom.offsetTop - dragDomheight;

    // 获取到的值带px 正则匹配替换
    let styL = sty(dragDom, 'left');
    let styT = sty(dragDom, 'top');
    // 注意在ie中 第一次获取到的值为组件自带50% 移动之后赋值为px
    if (styL.includes('%')) {
      styL = +document.body.clientWidth * (+styL.replace(/\%/g, '') / 100);
      styT = +document.body.clientHeight * (+styT.replace(/\%/g, '') / 100);
    } else {
      styL = +styL.replace(/\px/g, '');
      styT = +styT.replace(/\px/g, '');
    }

    document.onmousemove = function (e) {
      // 通过事件委托，计算移动的距离
      let left = e.clientX - disX;
      let top = e.clientY - disY;
      // 边界处理
      if (-(left) > minDragDomLeft) {
        left = -(minDragDomLeft);
      } else if (left > maxDragDomLeft) {
        left = maxDragDomLeft;
      }
      if (-(top) > minDragDomTop) {
        top = -(minDragDomTop);
      } else if (top > maxDragDomTop) {
        top = maxDragDomTop;
      }
      // 移动当前元素
      dragDom.style.cssText += `;left:${left + styL}px;top:${top + styT}px;`;
    };
    document.onmouseup = function (e) {
      document.onmousemove = null;
      document.onmouseup = null;
    };
  }
}

/** 最大化方法 */
function resize(el) {
  //获取弹框头部（这部分可双击全屏）
  const dialogHeaderEl = el.querySelector('.el-dialog__header');
  //弹窗
  const dragDom = el.querySelector('.el-dialog');
  //清除选择头部文字效果
  dialogHeaderEl.onselectstart = new Function("return false");
  let resizeEvent = new CustomEvent('drag-resize', {detail: '尺寸变化', bubbles: false});
  //初始化不最大化
  el.fullscreen = false;
  //记录初始宽高、顶部高度
  let nowWidth = dragDom.offsetWidth;
  let nowHight = dragDom.offsetHeight;
  let nowMarginTop = dragDom.style.marginTop;
  let hasSetBodyHight = false;
  //头部插入最大化最小化元素
  let maxMin = document.createElement("button");
  maxMin.className += ' el-dialog__headerbtn el-dialog__minmax';
  maxMin.style.right = '40px';
  maxMin.style.color = '#909399';
  maxMin.title = el.fullscreen ? '还原' : '最大化';
  maxMin.innerHTML = '<i class=' + (el.fullscreen ? '"el-icon-crop"' : '"el-icon-full-screen"') + ' onMouseOver="this.style.color=\'#409EFF\'" onMouseOut="this.style.color=\'inherit\'"></i>';
  dialogHeaderEl.insertBefore(maxMin, dialogHeaderEl.childNodes[1]);
  let bodyHeight = 'auto';

  function setMaxMin() {
    if (el.fullscreen) {
      dragDom.className = dragDom.className.replaceAll(' el-zoom-dialog', '');
      let i = maxMin.querySelector('.el-icon-crop');
      i.classList.remove('el-icon-crop');
      i.classList.add('el-icon-full-screen');
      maxMin.innerHTML = '<i class="el-icon-full-screen"></i>';
      maxMin.title = '最大化';
      dragDom.style.height = nowHight + 'px';
      dragDom.style.width = nowWidth + 'px';
      dragDom.style.marginTop = nowMarginTop + 'px';
      el.fullscreen = false;
      // dialogHeaderEl.onmousedown = moveDown;
      dragDom.querySelector('.el-dialog__body').style.height = bodyHeight;
      hasSetBodyHight = false;

      // 重新绑定拖拽事件,解决缩放后拖拽不生效问题
      if (dragDom.className.indexOf('el-drag-dialog') !== -1) {
        drag(el);
      }
    } else {
      dragDom.className += ' el-zoom-dialog';
      let i = maxMin.querySelector('.el-icon-full-screen');
      i.classList.remove('el-icon-full-screen');
      i.classList.add('el-icon-crop');
      maxMin.title = '还原';
      bodyHeight = dragDom.querySelector('.el-dialog__body').offsetHeight + 'px';
      nowHight = dragDom.clientHeight;
      nowWidth = dragDom.clientWidth;
      nowMarginTop = dragDom.style.marginTop;
      dragDom.style.left = 0;
      dragDom.style.top = 0;
      dragDom.style.height = "100VH";
      dragDom.style.width = "100VW";
      dragDom.style.marginTop = 0;
      el.fullscreen = true;
      dialogHeaderEl.onmousedown = null;
      if (!hasSetBodyHight) {
        let footerHeight = dragDom.querySelector('.el-dialog__footer') && dragDom.querySelector('.el-dialog__footer').offsetHeight;
        dragDom.querySelector('.el-dialog__body').style.height = 'calc(100vh - ' + (dialogHeaderEl.offsetHeight + footerHeight) + 'px)';
        hasSetBodyHight = true;
      }
    }
    el.dispatchEvent(resizeEvent);
  }

  //点击放大缩小效果
  maxMin.onclick = setMaxMin;
  //双击头部效果
  dialogHeaderEl.ondblclick = setMaxMin;
  //拉伸
  let resizeEl = document.createElement("div");
  dragDom.appendChild(resizeEl);
  //在弹窗右下角加上一个10-10px的控制块
  resizeEl.style.cursor = 'se-resize';
  resizeEl.style.position = 'absolute';
  resizeEl.style.height = '10px';
  resizeEl.style.width = '10px';
  resizeEl.style.right = '0px';
  resizeEl.style.bottom = '0px';
  //鼠标拉伸弹窗
  resizeEl.onmousedown = (e) => {
    // 记录初始x位置
    const clientX = e.clientX;
    // 鼠标按下，计算当前元素距离可视区的距离
    const disX = e.clientX - resizeEl.offsetLeft;
    const disY = e.clientY - resizeEl.offsetTop;
    document.onmousemove = function (e) {
      e.preventDefault(); // 移动时禁用默认事件
      // 通过事件委托，计算移动的距离
      const x = e.clientX - disX + (e.clientX - clientX);//这里 由于elementUI的dialog控制居中的，所以水平拉伸效果是双倍
      const y = e.clientY - disY;
      //比较是否小于最小宽高
      dragDom.style.width = x > nowWidth ? `${x}px` : nowWidth + 'px';
      dragDom.style.height = y > nowHight ? `${y}px` : nowHight + 'px';
      if (!hasSetBodyHight) {
        let footerHeight = dragDom.querySelector('.el-dialog__footer') && dragDom.querySelector('.el-dialog__footer').offsetHeight;
        dragDom.querySelector('.el-dialog__body').style.height = 'calc(100% - ' + (dialogHeaderEl.offsetHeight + footerHeight) + 'px)';
        hasSetBodyHight = true;
      }
    };
    //拉伸结束
    document.onmouseup = function (e) {
      document.onmousemove = null;
      document.onmouseup = null;
      el.dispatchEvent(resizeEvent);
    };
  }
}
